.bg{
    background: url('../../image/12.jpg');
    /* opacity: 0.5; */
    height: 100%;
}
.form{
    width: 600px;
    height: 400px;
    background: #fff;
    border-radius:20px ;
    padding: 20px 0 20px 20px;
    position:absolute;
    top:0;
    right:0;
    bottom:0;
    left:0;
    margin: auto;
}